Bornean Orangutan, Pongo pygmaeus, is a species of
orangutan native to the island of Borneo. Together with
the slightly smaller Sumatran Orangutan, it belongs to
the only genus of great apes native to Asia.
The Bornean Orangutan has a life span of about 35 to 40
years in the wild; in captivity it can live to be 60. A
survey of wild orangutans found that males are typically
75 kg (165 lb) and 1.2-1.4 m (4-4.7 ft) long; females
averaging 38.5 kg (82 lb) and 1-1.2 m (3.3-4 ft) long
There is evidence that there was gene flow between the
geographically isolated Bornean Orangutan populations
until recently. The Bornean and Sumatran Orangutan
species diverged 1.5 – 1.7 million years ago. This
occurred well before the two islands (Borneo and
Sumatra) separated. The two species of orangutan are
more distantly related than the Common Chimpanzee and
the Bonobo. Despite the difference, the two orangutan
species were only considered subspecies until as
recently as 1996, following sequencing of mtDNA.
The Bornean Orangutan has three subspecies:
* Northwest Bornean Orangutan P. p. pygmaeus - Sarawak
(Malaysia) & northern West Kalimantan (Indonesia)
* Central Bornean Orangutan P. p. wurmbii - Southern
West Kalimantan & Central Kalimantan (Indonesia)
* Northeast Bornean Orangutan P. p. morio - East
Kalimantan (Indonesia) & Sabah (Malaysia)
The population currently listed as P. p. wurmbii may be
closer to the Sumatran Orangutan (P. abelii) than the
Bornean Orangutan. If confirmed, abelii would be a
subspecies of P. wurmbii (Tiedeman, 1808). Regardless,
the type locality of pygmaeus has not been established
beyond doubts, and may be from the population currently
listed as wurmbii (in which case wurmbii would be a
junior synonym of pygmaeus, while one of the names
currently considered a junior synonym of pygmaeus would
take precedence for the taxon in Sarawak and northern
West Kalimantan). To further confuse, the name morio, as
well as various junior synonyms that have been
suggested, have been considered likely to all be
junior synonyms of the population listed as pygmaeus in
the above, thus leaving the taxon found in East
Kalimantan and Sabah unnamed.
The Bornean Orangutan lives in tropical and subtropical
moist broadleaf forests in the Bornean lowlands as well
as mountainous areas 1500 m in elevation. It lives at
different heights in the trees and moves large distances
to find trees bearing fruit. Its diet consists of fruit
as well as shoots, bark, mineral rich soil and bird
eggs. It also eats insects but to a lesser extent than
the Sumatran Orangutan.
The Bornean Orangutan travels on the ground more than
its Sumatran counterpart. It is theorized this may be in
part because there is no need to avoid the large
predators which only exist in Sumatra such as the
The Bornean Orangutan is more solitary than the Sumatran
Orangutan. Two or three orangutans that have overlapping
territories may interact for small periods of time.
Males and females generally come together only to mate.
Rape is common among orangutans. Sub-adult males will
try to mate with any female, though they probably mostly
fail to impregnate them since mature females are easily
capable of fending them off. Mature females prefer to
mate with mature males.
Newborn orangutans nurse every 3 to 4 hours, and begin
to take soft food from their mothers' lips by 4 months.
the first year of its life the baby clings to its
mother's abdomen by entwining its fingers in and
gripping her fur. Babies stay with their mothers until
they are about 8 or 9 years old and have a long
childhood compared to other apes.